Question

# Why is water considered a compound?

In water, two different elements combine together to form a single molecule. The elements are hydrogen and oxygen. The composition of water can be given as ${H_2}O$ in which two hydrogens combine with one oxygen atom in the ratio $2:1$ to produce one molecule of water.
$2{H_2}(g) + {O_2}(g)\xrightarrow{{}}2{H_2}O(g)$
Practically to generate two molecules of water, two molecules of diatomic hydrogen (${H_2}$) react with one molecule of diatomic oxygen (${O_2}$). Energy will be released in the process. This reaction generally occurs in fuel cells.
The $O$ in water molecule carries two electron pairs and can associate with another water molecule which leads to the formation of ice on freezing. In organic chemistry, it is used as an environmentally friendly solvent. Water can coordinate with several types of organic and inorganic compounds viz. acids, alcohols, etc.